I have an old lotus ive been overhauling with SR super custom cranks (170's). I rode the bike for a bit with the left crank loose, and I think its now too worn to really warrant putting it back on. It rides ok if I do, but slowly loosens again over time, and I dont think lock tighting the bolt would be the best idea. The rest of the bike is 600EX arabesque components.

Ideally id just like to replace the left crank arm as the crankset and chainrings and whatnot are in perfect condition, but its hard to find an SR crankset these days. What can I replace this with? Should I just get a used crankset, and what would be my cheapest option?

probably you can find a set of shimano 600ex crancks at ebay. When shimano came with the new 600 the old design went to the upcomming shimano 105. They looked the same but the 105 color was lighter.

I would try to do that 1st, either way any crankset will work with downtube shifters.

I found a new set of shimano 600EX cranks on ebay, b ut they are going up in price quick.

So any crankset will work? Isnt my chain / derailleurs not compatible with many?

I got this 600 Arabesque on eBay for $30 and the bottom bracket came with it. I had to do a lot of cleaning and polishing.

No compatability issues with the chain or derailer, but you have to have the correct BB spindle length for the crank. That's why it's always best to get the bottom bracket with the crank.

Interesting.....I may go with the 600 then. Oddly enough Im not really sure why my bike has super custom cranks ( I think my parents may have upgraded it years ago before I inherited it) as I have the original manual for the bicycle and it says it comes with the 600 cranks......

Are the 600EX cranks very heavy? Would I be better off to go with something else that is vintage yet a bit newer / lighter?

600EX cranks aren't that heavy. 600 arabesque cranks are sometimes found on eBay. I have a set of SR cranks but they are for cottered spindles. If you've got a square taper bb, you've got options from Sugino to Shimano to Suntour to SR, even Miche. They all fit, and some are quite nice, and you should be able to get a set very reasonably.

Yea, I have square taper BB ( I guess, it seems to taper a bit....). I just re greased t he bearings too with white lithium, gonna put the bike back together in the next few days.

edit: I found a pair of newer shimano 600 crank arms (no rings, just the arms). They are 172.5 mm in length instead of 170 however, will I have problems with this? I cant really see the 2mm making a difference (hopefully I dont scrape on the ground while turning....)

Will they fit my current rings? The rings I have are basically perfect condition

Any set of cranks will work with your set up, as long as u get the bb also. If you use down tube shifters that does not have index, you can mix any brand of RDs, fd, cogs, wheels, cranksets.

Downtube shifters are awesome but lets face, campagnolo ergo is better hehehe

Get a pair of 600s at ebay, done. Regarding chain, a 7sp or 8 sp chain will work too.

Nice, thanks guys! How can I measure the BCD of my current rings?

I have my shifters (non indexed of course) mounted on the handlebars, so they are good enough as is. This bike is mainly for commuting / touring, I have my cross bike with full DA for going fast

Are the handle bar mounted shifters Arabesque style? I'm rebuilding an 80's road bike using Arabesque components, most of which are NOS. The shifters are down tube type that I want to move to the stem.
Can you post a picture of your shifters showing how thet are mounted?

thanks,

GB

I have some type of small adapter that attaches to the stem (LBS did it). Not too sure what its called